Method of preparing finelydivided wax



United States Patent 3,152,917 METHGD 0F PREPARING FHNELY- DIVIDEE) WAX Frederic C. Mciioy, Beacon, Edwin C. Knowles, Poughkeepsie, and Howard V. Hess, Glenham, N.Y., assignors to Texaco Inc, New York, N.Y., a corporation of Delaware No Drawing. Filed June 1, 1961, Ser. No. 114,028 1 Claim. (Cl. 106-271) consisting of hydrocarbons and derivatives of hydrocarbons preferably having not less than 6 carbon atoms in the hydrocarbon chain or ring, as described more fully hereinbelow. The hydrocarbon or the derivative thereof undergoing treatment may be normally solid at room temperature and atmospheric pressure, or if normally a liquid, the material is rendered solid under the conditions of temperature and pressure employed in carrying out the method of this invention. In either case, the hydrocarbon or derivative thereof is dissolved or diluted in a suitable liquid solvent, preferably organic liquid solvent, which does not react with the hydrocarbon or derivative. The resulting solution is contacted under agitation with a dissociating liquid in which the hydrocarbon or derivative thereof is relatively insoluble and which is substantially miscible with the solvent for the hydrocarbon or derivative thereof. The dissociating liquid is relatively cool in comparison with the melting point of the material being prepared in finely-divided form. Upon agitation, the hydrocarbon or the derivative thereof separates from the mixture as a finely-divided material which is recovered by filtration, centrifuging, or the like.

Hydrocarbon materials and derivatives thereof found particularly suitable for our invention, and which therefore may be prepared in finely-divided form, include straight and branched chain aliphatic hydrocarbons and aromatic hydrocarbons, i.e., benzene, naphthalene, etc., and derivatives of aliphatic and aromatic hydrocarbons including oxygen, halogen and amine derivatives. The hydrocarbons and derivatives thereof preferably have not less than 6 carbon atoms in the hydrocarbon chain or ring and the hydrocarbon chain or ring may be saturated or contain an unsaturated linkage. A wide variety of terminal groups or radicals may be provided'at one end of the chain or attached to the ring including alcohol, aldehyde,

olefin, ketone, halogen and carboxyl groups. Derivatives of aliphatic hydrocarbons may include, for example, the fatty acids such as sebacic acid, stearicacid, oleic acid, palmitic acid and linoleic acid, or their salts such as zinc stearate, etc.; the aliphatic alcohols, such as searyl alcohol and palmityl alcohol; the aliphatic amines and amides,

such. as stearyl amine and stearamide; and the halogenated initially in a liquid solvent. These solvents in which the v 3,152Q9l7 Patented Get. 13, 1964 "ice material is dissolved or diluted include the normally liquid polar aliphatic organic compounds. This includes for example, the alkanols, such as methanol, ethanol, propanol, isopropanol, isobutanol, n-butanol, tertiary butyl alcohol; the various ketones, such as acetone, methylethyl ketone, diacetone alcohol, dioxane, methyl n-butyl ketone, methylisobutyl kctone, tetrahydrofuran; and aqueous solutions of the foregoing. In general, any normally liquid polar aliphatic organic compound containing from 1 to 6 carbon atoms per molecule can suitably be employed. Other polar solvents which may suitably be employed include the low boiling amines such as ethylamine; the low boiling mercaptans such as ethyl mercaptan; the olefinic glycols such as monoethylene glycol; the alkanolamines such as ethanolamine; or mixtures thereof such as aqueous solutions of methanol and monoethylene glycol. The liquid solvent should be substantially devoid of those compounds or hydrocarbons which react with the hydrocarbon or hydrocarbon derivative.

The resulting solution is contacted under agitation with a dissociating liquid, for example water, in which the hydrocarbon or derivative thereof is relatively insoluble and which is substantially miscible with the liquid solvent. Thus, for example, the water may be agitated as the solution of material is added to the water. The Water as the dissociating liquid, is maintained at a relatively cool temperature, preferably not less than 10 F. cooler than the melting point of the final product prepared in powdered form. It is advantageous to employ an excess of water in order that the solution of material may be completely immersed in the aqueous mixture. Agitation, as used herein and in the appended claims, is defined as violent and irregular movement whereby intimate contact between the solution of the material and water occurs and discrete particles of the hydrocarbon or derivative thereof undergoing treatment separate. If the solution (or solutions) upon contact or mixing is not agitated, or if only mildly stirred, the material undergoing treatment will agglomerate. Agitation may be satisfactorily accomplished by high speed stirring, as for example with paddle stirrers or impeller stirrers rotating at high speeds, or with a turbine mixer, mixing valve, centrifugal pump, orifice nozzle, etc. This treatment dissociates the material into discrete particles of the hydrocarbon or derivative undergoing treatment which separate from the remaining aqueous mixture in finely-divided form,-the solvent being dissolved by the water. The fine particles of the hydrocarbon or derivative may be separated from the remaining aqueous mixture by filtration and dried by conventional means, if desired, to recover the hydrocarbon or derivative in powder form.

The liquid employed in the dissociating step is dependent to some extent upon the melting point of the material undergoing treatment. Where the hydrocarbon or derivative being prepared in finely-divided form is normally solid at room temperature and atmospheric pressure, water may be conveniently andeconomically used as the dissociating liquid. This invention also contemplates preparation of finely-divided materials which are normally liquid, that is, solid only at relatively low tem peratures. In this event, it may be desirable, ,or often necessary to use a dissociating liquid havinga'relatively low freezing point as compared to that of water. Thus,

organic liquids, particularly the alkanols and ketones having 1 to 3 carbon atoms and aqueous mixtures thereof, for example, methanol, ethanol and acetone, and liquid ammonia or liquid sulfur dioxide may be advantageously employed. However, the invention is particularly applicable in the preparation of finely-divided materials which are normally solid, and therefore the invention has been described in more detail in connection with the use of water as the particular dissociating liquid, although it is understood that other liquids are applicable.

Where desired, a minor amount of a suitable surface active agent such as the sodium sulfonates may be incorporated in the solution of the material to be prepared in powdered form. Thesurface active agent facilitates separation of the finely-divided hydrocarbon or derivative from the aqueous mixture, and reduces the quantity of water entrained by the recovered product. The choice of surface active agent is determined largely by the materials employed in the process, and may be anionic, cationic or non-ionic. About 0.01 to 0.2% by weight of surface active agent may be incorporated, preferably by dissolving the agent in the polar solvent, but smaller or larger amounts may be used where desired.

In addition, a small amount of a micro-dimensional silica powder which is hydrophobic may be incorporated in the powdered product. The amount of silica powder used depends somewhat upon the hydrocarbon or derivative being treated, but generally about 0.2 to 3% by weight is satisfactory. The silica powder facilitates the separation of the finely-divided hydrocarbon material from the aqueous mixture, and further assists in maintaining the powdered hydrocarbon or derivative in a dry condition and therefore free-flowing.

Our invention is further illustrated by the following examples.

Example I About 0.5 gram of hydrophobic silica powder was added to the aqueous mixture and again agitated on the Waring Blendor for 30 seconds. The aqueous mixture then was filtered, and the filtrate was dried for four hours. About grams of powdered paratfin wax having a fine particle size were recovered.

Example II The procedure according to Example I was repeated,

except that methylethyl ketone was employed as the solvent for the paralfin wax in place of tetrahydrofuran. About 8 grams of a uniform, finely divided powder of paraffin wax were recovered.

Example III 10 grams of stearic acid were added to 50 milliliters of acetone, and dissolved upon warming on a steam plate. The resulting solution was added slowly to 300 milliliters of cold tap water subject to agitation in a Waring Blendor as in Example 1. After all the solution had been added, agitation in the blendor was continued for an additional 30 seconds. 0.5 gram of hydrophobic silica powder was added, and the mixture again agitated, filtered and dried,

as in Example I. A uniform, finely divided powder product was recovered weighing about 10.5 grams.

Example IV The procedure acording to Example 111 was repeated except that palmitic acid was substituted for the'stearic acid. The process yielded about 10 grams of palmitic acid as finely divided powder.

Example V Cetyl alcohol was substituted for the stearic acidi ot Example III, and upon treatment of the solution as in Example III, about 8 grams of cetyl alcohol as a uniform powder were recovered.

Example V1 10 grams of stearamide were added to 70 milliliters of tetrahydrofuran and dissolved therein upon warming on a steam plate. Upon treatment as in Example 111, stearamidein fine powdered form was recovered, the final product having a total weight of about 10.3 grams.

' Exam le VII l0 grams of naphthalene were dissolved in 50 milliliters of acetone. The resulting solution was added to 500 milliliters of cold tap water subject to agitation in a WaringBlen'doras in the previous examples. The mixture was filtered on a Biichner funnel, and sucked dry thereon, whereby a very fine crystalline powder resulted.

Example VH1 Example IX The procedure according to Example VII was repeated,

except 10 grams of 2,6-di-tertiary-butyl-para-cresol was substituted for the naphthalene. 0.3 gram of hydrophobic silica powder was added to the finely-divided powder obtained upon filtration thereby resulting in a fiowaole powder.-

Example X 10 grams of {B-naphthol were dissolved in 50 milliliters of acetone and the resulting solution was added to 500 milliliters of cold tap water subject to agitation in a Waring Blendor. Upon filtration and drying at room temperature, about 9 grams of finely-divided powder were recovered.

' Example XI The procedure according to Example X was repeated, except that 12.5 grams of p-dichlorobenzene were substituted for the ,B-naphthol. Upon filtration and drying, about 12.3 grams of a fine powder product were recovered.

We claim: I

A method of preparing a finely-divided paraffin wax comprising dissolving paraffin wax in tetrahydrofuran, contacting the resultant solution with water maintained at a temperature at least 10, F. below that of the melting point of said 'paraflin wax,whereby finely-divided solid parafiin wax particles are formed in the resultant aqueous mixture, admixing hydrophobic silica powder in said resultant aqueous mixture and subsequently recovering the hydrophobic silica treated finely-divided wax particles from the aqueous mixture, saidcontacting and said admixing conducted under agitationconditions suificient to cause violent and irregular movement of the aqueous mixture.

References Cited in the file of this patent UNITED STATES PATENTS I Germany; Aug. 8, 1932 

